rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6502/1:b..l rcu: (detected by 1, t=10502 jiffies, g=22673, q=743 ncpus=2) task:syz.0.304 state:R running task stack:25904 pid:6502 tgid:6498 ppid:5547 flags:0x00004002 Call Trace: <TASK> context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:srso_alias_safe_ret+0x0/0x7 arch/x86/lib/retpoline.S:171 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <48> 8d 64 24 08 c3 cc e8 f4 ff ff ff 0f 0b cc cc cc cc cc cc cc cc RSP: 0018:ffffc900031af730 EFLAGS: 00000297 RAX: 0000000000000002 RBX: 0000000000000003 RCX: ffff888029fa5a00 RDX: ffffc9000c0ed000 RSI: 0000000000000003 RDI: 0000000000000002 RBP: dffffc0000000000 R08: ffffffff8b8b830f R09: 1ffffffff25fdab8 R10: dffffc0000000000 R11: fffffbfff25fdab9 R12: ffffc900031af840 R13: 0000000000000003 R14: ffffc900031af858 R15: 1ffff92000635f0b srso_alias_return_thunk+0x5/0xfbef5 arch/x86/lib/retpoline.S:181 xa_is_internal include/linux/xarray.h:175 [inline] xa_is_err include/linux/xarray.h:207 [inline] xa_err include/linux/xarray.h:226 [inline] xas_error include/linux/xarray.h:1431 [inline] xas_start+0x5f/0x7b0 lib/xarray.c:187 xas_load+0x2c/0x5c0 lib/xarray.c:238 filemap_get_entry+0x1f0/0x3b0 mm/filemap.c:1840 shmem_get_folio_gfp+0x2a8/0x1f50 mm/shmem.c:1993 shmem_get_folio mm/shmem.c:2171 [inline] shmem_write_begin+0x170/0x4d0 mm/shmem.c:2754 generic_perform_write+0x39b/0x840 mm/filemap.c:4019 shmem_file_write_iter+0xfc/0x120 mm/shmem.c:2930 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa74/0xc90 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4a3b9746df RSP: 002b:00007f4a3c68ae00 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000100000 RCX: 00007f4a3b9746df RDX: 0000000000100000 RSI: 00007f4a31600000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000009de43 R10: 000000002009e802 R11: 0000000000000293 R12: 0000000000000003 R13: 00007f4a3c68af00 R14: 00007f4a3c68aec0 R15: 00007f4a31600000 </TASK> rcu: rcu_preempt kthread starved for 10419 jiffies! g22673 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:24912 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111